With the development of communication technology and value-added service, more and more mobile terminal applications have been developed, and user experience is getting better and better. A “preview” is a useful sub-application, which is used in many application programs. Through “preview,” a user can see the effect of running the application before determining a final application.
Currently, the “preview” sub-application is implemented by “overlaying” a selected picture of a target application on a simulated environment, so as to provide a simulation style “similar to” a real application scenario. That is, a background picture is preset and then a picture of the target application is “overlaid” on the background picture, as shown in FIG. 1, taking a desktop clock application as an example.